Bret Oberg, age 10, of Monroe, La., for his question:

WHEN WAS THE PLANET URANUS DISCOVERED?

Uranus is the seventh planet from the sun. Only Neptune and Pluto are farther away. The planet, which is almost four times larger in diameter than the earth, was discovered in 1781 by a British astronomer named Sir William Herschel.

Uranus travels around the sun in an oval shaped orbit. It takes the planet about 84 earth years to go around the sun.

Uranus rotates on its axis, an imaginary line through its center, as it orbits the sun. The axes of most planets are almost perpendicular (at an angle of 90 degrees) to the planets' paths around the sun. But the axis of Uranus is tilted 98 degrees from the perpendicular position, so that it is almost level with the planet's path around the sun.

Uranus takes 10 hours and 49 minutes to spin on its axis. The large angle of tilt and the rapid spin of the planet make it appear to roll along in its orbit.

Uranus has five small satellites or moons moving around it. Its surface is covered with clouds.